Coupled Systems Mechanics
Volume 13, Number 3, 2024, pages 201-217
DOI: 10.12989/csm.2024.13.3.201
Minimum area for circular isolated footings with eccentric column taking into account that the surface in contact with the ground works partially in compression
Inocencio Luévanos-Soto, Arnulfo Luévanos-Rojas, Victor Manuel Moreno-Landeros and Griselda Santiago-Hurtado
Abstract
This study aims to develop a new model to obtain the minimum area in circular isolated footings with eccentric column taking into account that the surface in contact with the ground works partially in compression, i.e., a part of the contact area of the footing is subject to compression and the other there is no pressure (pressure zero). The new model is formulated from a mathematical approach based on a minimum area, and it is developed by integration to obtain the axial load "P", moment around the X axis "Mx" and moment around the Y axis "My" in function of omax (available allowable soil pressure) R (radius of the circular footing), a (angle of inclination where the resultant moment appears), y0 (distance from the center of the footing to the neutral axis measured on the axis where the resultant moment appears). The normal practice in structural engineering is to use the trial and error procedure to obtain the radius and area of the circular footing, and other engineers determine the radius and area of circular footing under biaxial bending supported on elastic soils, but considering a concentric column and the contact area with the ground works completely in compression. Three numerical problems are given to determine the lowest area for circular footings under biaxial bending. Example 1: Column concentric. Example 2: Column eccentric in the direction of the X axis to 1.50 m. Example 3: Column eccentric in the direction of the X axis to 1.50 m and in the direction of the Y axis to 1.50 m. The new model shows a great saving compared to the current model of 44.27% in Example 1, 50.90% in Example 2, 65.04% in Example 3. In this way, the new minimum area model for circular footings will be of great help to engineers when the column is located on the center or edge of the footing.
Key Words
axial load; circular isolated footings; minimum area; moment around the X axis; moment around the Y axis; surface in contact with the ground works partially in compression
Address
Inocencio Luévanos-Soto: Instituto de Investigaciones Multidisciplinaria, Universidad Autónoma de Coahuila, Blvd. Revolución No, 151 Ote, CP 27000, Torreón, Coahuila, México
Arnulfo Luévanos-Rojas, Victor Manuel Moreno-Landeros: Facultad de Ingeniería, Ciencias y Arquitectura, Universidad Juárez del Estado de Durango, Av. Universidad S/N, Fracc. Filadelfia, CP 35010, Gómez Palacio, Durango, México
Griselda Santiago-Hurtado: Facultad de Ingeniería Civil, Universidad Autónoma de Coahuila, CP 27276, Torreón, Coahuila, México